Lubrication apparatus in power transmission unit

Abstract

A lubrication apparatus in a vehicular power transmission unit includes device pinion shaft which is rotatably supported by a bearing disposed at a rear end portion of a casing. The casing contains lubricating fluid. A pickup member is disposed on the drive pinion shaft and picks up lubricating fluid upon rotation of the drive pinion shaft. A trough is formed on a wall of the casing in an inclined relation to the axis of the drive pinion shaft. The trough receives the lubricating fluid which is picked up and allows the lubricating fluid to flow under the influence of gravity to the rear end portion of the casing for lubricating the bearing located thereof.

What is claimed is:  
     
       1. A lubrication apparatus in a power transmission unit in a motor vehicle, comprising: 
       a rotatable shaft;  
       a casing receiving said shaft, said casing having end portions spaced in a direction of the axis of said shaft;  
       a bearing supporting said shaft, said bearing being disposed at an axial end portion of said casing;  
       a pickup member carried on said shaft; and  
       a trough which extends along a side of said casing from said bearing to a position which is at least opposite said pickup, said trough being open to an interior of the casing along its length, and inclined along its length relative to an axis of said shaft to allow lubricating fluid, picked up by said pickup member and flung into the trough via its rotation, to flow, under the influence of gravity, toward the bearing, the inclination of the trough being selected to be steeper than a maximum angle with respect to the horizontal to which the shaft can become tilted to permit lubricating fluid to flow to said bearing under the influence of gravity even when the shaft is tilted to the maximum angle, the maximum angle being a critical angle for stability of the motor vehicle at which the motor vehicle can be prevented from slipping down when the motor vehicle is stopped on a slope.  
     
     
       2. A lubrication apparatus as claimed in claim  1 , wherein the trough is essentially straight along its whole length when viewed from a transverse angle respect to the shaft. 
     
     
       3. A lubrication apparatus as claimed in claim  1 , wherein the trough has a narrowed portion proximate the bearing.